Question 1066011: Two dice are rolled simultaneously the score is the sum of numbers the dice land on. Find the probability that
a) the score is divisible by 3 or divisible by 4.
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! Divisible evenly by 3 (edited) includes 3,6,9,12
probability of each is 2/36, 5/36, 4/36, and 1/36 or 12/36 or (1/3)
Divisible by 4 includes 4,8,12 or 3/36, 5/36, 1/36 or 9/36 (1/4)
If the question includes divisible by 3 OR divisible by 4, then we can look at the others and subtract from 1:
That would be 2,5,7,10,11, which are 1,4,6,3,2=16/36; subtracted from 1 is 20/36 or 5/9.
Check with summing the two above (21/36) and subtracting double counted (12, which is 1/36) and get 20/36 or 5/9.
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